Ohms Law Low-current Calibration System for Ionization Chambers
Dean G. Jarrett, Shamith U. Payagala, Ryan P. Fitzgerald, Denis E. Bergeron, Jeffrey T. Cessna, Charles J. Waduwarage Perera, Neil M. Zimmerman
A system for the calibration of electrometers that measure currents from ionization chambers is described. The calibration system uses a 1 GΩ standard resistor in series with a stable voltage source to generate calibration currents from 1 pA to 20 nA, traceable to quantum voltage and resistance standards through an 8-1/2 digit digital voltmeter and the standard resistor. Expanded uncertainties (k = 2) of 100 x 10-6 or better for the calibration of the electrometer is needed for the ionization chamber measurements. The electrometer calibration was verified by current measurements following the decay of the short-lived radionuclide 18F in a re-entrant ionization chamber.
2020 Conference on Precision Electromagnetic Measurements(CPEM 2020)
August 24-28, 2020
electrometer, ionization chamber, quantum electrical standards, standard resistor, small current measurement
, Payagala, S.
, Fitzgerald, R.
, Bergeron, D.
, Cessna, J.
, Waduwarage, C.
and Zimmerman, N.
Ohms Law Low-current Calibration System for Ionization Chambers, 2020 Conference on Precision Electromagnetic Measurements(CPEM 2020), Denver, CO
(Accessed September 21, 2021)